Fluidising composition

Abstract

A fluidising admixture for use with sprayable cementitious compostions, the admixture consists of 2-phosphonobutane-1,2,4-tricarboxylic acid and at least one selected polymer derived from ethylenically-unsaturated mono- or dicarboxylic acids. Citric acid may optionally be present. The admixture has good fluidising properties and outstanding shelf-life.

1 . A fluidising admixture for use with sprayable cementitious compositions, the admixture consisting of: 
 (1) 2-phosphonobutane-1,2,4-tricarboxylic acid;    (2) optionally, citric acid; and    (3) at least one polymer derived from ethylenically-unsaturated mono- or dicarboxylic acids, and characterised in that the polymer consists of:    a) 51-95 mole % of moieties of formula 1a and/or 1b and/or 1c                          wherein R 1 =hydrogen or a C 1-20  aliphatic hydrocarbon residue; 
 X═O a M, —O—(C m H 2m O) n —R 2 , —NH—(C m H 2m O) n —R 2 ,  
 M=hydrogen, a mono- or divalent metal cation, an ammonium ion or an organic amine residue;  
 a=0.5 or 1;  
 R 2 =hydrogen, C 1-20  aliphatic hydrocarbon, C 5-8  cycloaliphatic hydrocarbon or optionally substituted C 6-14  aryl residue;  
 Y═O, NR 2 ;  
 m=2-4; and  
 n=0-200;  
   b) 1-48.9 mole % of moieties of the general formula II                          wherein R 3 =hydrogen or C 1-5  aliphatic hydrocarbon; 
 p=0-3; and  
 R 2  has the meaning given previously;  
   c) 0.1-5 mole % of moieties of Formulae IIIa or IIIb                          wherein                        —W—R 7      —CO—[NH—(CH 2 ) 3 ] s —W—R 7      —CO—O—(CH 2 ) z —W—R 7      —(CH 2 ) z —V—(CH 2 ) z —CH═CH—R 2      ═—COOR 5  when S is —COOR 5  or COO a M    U 1 ═—CO—NH—, —O—, —CH 2 O—   U 2 ═—NH—CO—, —O—, —OCH 2 —   V═—O—CO—C 6 H 4 —CO—O— or —W—                         R 4 ═H, CH 3      R 5 ═a C 3-20  alphatic hydrocarbon residue, a C 5 -C 8  cycloaliphatic hydrocarbon residue or a C 6-14  aryl residue;                            wherein r=2-100    s=1,2    z=0-4    x=1-150    y=0-15; and    d) 0-47.9 mole % of moieties of the general formula IVa and/or IVb:                          wherein a, M, X and Y have the meanings defined above.    
     
     
         2 . A fluidising admixture according to  claim 1 , in which: 
 a) the moiety is according to formula Ia; 
 R 1 , R 2  are independently H or CH 3 ;  
 X═O a M, —O—(C m H 2m O) n —R 2    
 M=H or a mono- or divalent metal cation;  
 a=1;  
 Y═O, NR 2 ;  
 m=2-3; and  
 n=20-150;  
   b) R 2 , R 3  are independently H or CH 3 ; and 
 p=0-1; and  
   c) the moiety is according to formula IIIa;                        —CO—[NH—(CH 2 ) 3 ] s —W—R 7  
 —CO—O—(CH 2 ) z —W—R 7    
 R 4 , R 5  are independently H, CH 3 ;  
                     
 wherein 
 x=20-50;  
 y=1-10; and  
 z=0-2.  
 
     
     
     
         3 . A fluidising admixture according to  claim 2 , in which: 
 a) the moiety is according to formula Ia; 
 R 1 ═H;  
 R 2 ═CH 3 ;  
 X═O a M;  
 M=a mono- or divalent metal cation;  
 Y═O, NR 2 ;  
 m=2; and  
 n=25-50;  
   b) R 2 , R 3 ═H; and 
 p=0; and  
   c) the moiety is according to formula IIIa;                        wherein 
 U 1 ═—CO—NH—;  
 U 2 ═—NH—CO—, —O—, —OCH 2 — 
 x=20-50;  
 y=5-10; and  
 z=1-2.  
     
     
     
         4 . A method of imparting flow to a cementitious composition, comprising the addition thereto of the admixture of  claim 1 .  
     
     
         5 . A method of spraying a cementitious composition comprising preparing a cementitious mix and conveying the mix to a spray nozzle, there being added to the mix at preparation the admixture of  claim 1 .  
     
     
         6 . The admixture of  claim 1  wherein the polymer has a weight-average molecular weight of from about 5,000 to about 50,000.  
     
     
         7 . The admixture of  claim 1  wherein the polymer has a weight-average molecular weight of from about 10,000 to about 40,000.  
     
     
         8 . The admixture of  claim 1  wherein the proportions of the solids of the three components are: 
 Component 1—about 1% to about 40%;    Component 2—0 to about 40%; and    Component 3—about 5% to about 60%.    
     
     
         9 . The method of  claim 4  wherein the admixture is added at a rate of from about 0.2% to about 2% by weight solids of cement.  
     
     
         10 . A fluidising admixture for use with sprayable cementitious compositions, the admixture comprising: 
 (1) 2-phosphonobutane-1,2,4-tricarboxylic acid;    (2) optionally, citric acid monohydrate; and    (3) at least one polymer derived from ethylenically-unsaturated mono- or dicarboxylic acids, and characterised in that the polymer comprises:    a) 51-95 mole % of moieties of formula 1a and/or 1b and/or 1c                          wherein R 1 =hydrogen or a C 1-20  aliphatic hydrocarbon residue; 
 X═O a M, —O—(C m H 2m O) n —R 2 , —NH—(C m H 2m O) n —R 2 ,  
 M=hydrogen, a mono- or divalent metal cation, an ammonium ion or an organic amine residue;  
 a=0.5 or 1;  
 R 2 =hydrogen, C 1-20  aliphatic hydrocarbon, C 5-8  cycloaliphatic hydrocarbon or optionally substituted C 6-14  aryl residue;  
 Y═O, NR 2 ;  
 m=2-4; and  
 n=0-200;  
   b) 1-48.9 mole % of moieties of the general formula II                          wherein R 3 =hydrogen or C 1-5  aliphatic hydrocarbon; 
 p=0-3; and  
 R 2  has the meaning given previously;  
   c) 0.1-5 mole % of moieties of Fonnulae IIIa or IIIb                          wherein                          —W—R 7  
 —CO—[NH—(CH 2 ) 3 ] s —W—R 7    
 —CO—O—(CH 2 ) z —W—R 7    
 —(CH 2 ) z —V—(CH 2 ) z —CH═CH—R 2    
 ═—COOR 5  when S is —COOR 5  or COO a M  
 U 1 ═—CO—NH—, —O—, —CH 2 O— 
 U 2 ═—NH—CO—, —O—, —OCH 2 — 
 V=—O—CO—C 6 H 4 —CO—O— or —W— 
                     
   R 4 ═H, CH 3  
 R 5 =a C 3-20  alphatic hydrocarbon residue, a C 5 -C 8  cycloaliphatic hydrocarbon residue or a C 6-14  aryl residue;  
                     
   wherein r=2-100 
 s=1, 2  
 z=0-4  
 x=1-150  
 y=0-15; and  
   d) 0-47.9 mole % of moieties of the general formula IVa and/or IVb:                          wherein a, M, X and Y have the meanings defined above.    
     
     
         11 . A fluidising admixture according to  claim 10 , in which: 
 a) the moiety is according to formula Ia; 
 R 1 , R 2  are independently H or CH 3 ;  
 X═O a M, —O—(C m H 2m O) n —R 2    
 M=H or a mono- or divalent metal cation;  
 a=1;  
 Y═O, NR 2 ;  
 m=2-3; and  
 n=20-150;  
   b) R 2 , R 3  are independently H or CH 3 ; and 
 p=0-1; and  
   c) the moiety is according to formula IIIa;                        —CO—[NH—(CH 2 ) 3 ] s —W—R 7      —CO—O—(CH 2 ) z —W—R 7  
 R 4 , R 5  are independently H, CH 3 ;  
                     
     wherein 
 U 1 ═—CO—NH—, —O—, —CH 2 O— 
 U 2 ═—NH—CO—, —O—, —OCH 2 — 
 x=20-50;  
 y=1-10; and  
 z=0-2.  
   
     
     
         12 . A fluidising admixture according to  claim 11 , in which: 
 a) the moiety is according to formula Ia; 
 R 1 ═H;  
 R 2 ═CH 3 ;  
 X═O a M;  
 M=a mono- or divalent metal cation;  
 Y═O, NR 2 ;  
 m=2; and  
 n=25-50;  
   b) R 2 , R 3 ═H; and 
 p=0; and  
   c) the moiety is according to formula IIIa;                          —CO—O—(CH 2 ) z —W—R 7  
 R 4 , R 5 ═H;  
                     
   wherein 
 U 1 ═—CO—NH—;  
 U 2 ═—NH—CO—, —O—, —OCH 2 — 
 x=20-50;  
 y=5-10; and  
 z=1-2.  
   
     
     
         13 . A method of imparting flow to a cementitious composition, comprising the addition thereto of the admixture of  claim 10 .  
     
     
         14 . A method of spraying a cementitious composition comprising preparing a cementitious mix and conveying the mix to a spray nozzle, there being added to the mix at preparation the admixture of  claim 10 .  
     
     
         15 . The admixture of  claim 10  wherein the polymer has a weight-average molecular weight of from about 5,000 to about 50,000.  
     
     
         16 . The admixture of  claim 10  wherein the polymer has a weight-average molecular weight of from about 10,000 to about 40,000.  
     
     
         17 . The admixture of  claim 10  wherein the proportions of the solids of the three components are: 
 Component 1—about 1% to about 40%;    Component 2—0 to about 40%; and    Component 3—about 5% to about 60%.    
     
     
         18 . The method of  claim 13  wherein the admixture is added at a rate of from about 0.2% to about 2% by weight solids of cement.